Study On The Auxiliary Power Supply System Of High Speed EMU

With the rapid development of high-speed railway technology in China, absorption for EMU technology has been an urgent problem in railway construction. As an important part of EMU, auxiliary power supply system not only acts as an assistant for the drawing motor, it also supplies electricity to maintain passengers'safety and rid environment. The main study includes four parts as below:(1) As the main part of the auxiliary power supply system, chief properties of converters were studied in detail. Firstly, topologies of some conventional converters were essentially elaborated; then, input/output responses of a number of converters and inverters, along with different modulation methods for inverters and corresponding controlling methods, were researched in detail; later, output responses of certain topologies were studied as the load changing through analog simulation, and frequency spectrums of the output waves were also analyzed.(2) Working patterns of auxiliary power supply systems for four kinds of EMU imported in China were analyzed, and their load situations were also studied. It's worth to note that, main loads in the auxiliary power supply system do not just include a series of superpower motors as in the past situations, power supply system for passengers are also considered as a part of it. In view of the above mentioned functional expansion in auxiliary power supply systems, some advices were submitted in this paper for design for auxiliary converters in high-speed trains.(3) For several kinds of auxiliary power supply systems, after profound analysis being done, detailed comparison and study were achieved according to operating efficiency, output voltage standard, proper/improper operating model and faulting. Based on above studies, an exceptional plan was found that, electric current should be taken off through the DC in the middle of the main rectification in the form of DC-AC current transformer model, and inputted to the AC bus through paralleled inverters.(4) Multi-inverters operated in the paralleled form were studied in detail. The mathematical expression for the circulating current, which is a main factor for the inverter parallel control technology, was deduced through studying on the equivalent topology. After that, effects of some key factors (such as amplitude, frequency and phase of the output voltage through inverters) on the circulating current were studied according to the expression. Furthermore, correctness of the above mentioned studies through the expression was validated according to the computer simulation.(5) Introduced four control strategies of parallel inverter and then were been simulated. Based on the result of the analysis, the MSC is proved to be a better strategy for auxiliary power supply system of EMU.